Monthly Archives: October 2013

The Tough Mudder is a 10-12 mile assault course:
“you can bank on plenty of mud, ice, fire, and electric shocks. We intend to make you earn that coveted orange headband…and the ice cold pint waiting for you at the finish line. Average completion time of a course is 3-4 hours.”

According to sale pitches from health and supplement shops, “caffeine is a powerful stimulant which can increase mental alertness and improve physical energy levels.” This is a well researched area and it has been shown on several accounts that caffeine has a positive effect on both endurance capacity and in reversing muscle fatigue (see references).

Caffeine and Biology?
Caffeine acts on the central nervous system, increasing alertness and concentration, which also stimulates adrenaline release and – in doses above 5mg/kg body weight – mobilizes fatty acid release. This means more fatty acids are used for energy and less glycogen, therefore increasing endurance. Caffeine can also increase the strength of muscle contractions which is advantageous for both anaerobic and aerobic activities.

The level of stimulation varies depending on several factors, including the amount used, the level of tolerance a person has to caffeine (as seen with habitual caffeine users), metabolism, and other drug use.

Coffee?
Drinking two cups of coffee an hour before exercise, may encourage your muscles to burn more fat and help you exercise longer and harder.

To make the most of its benefits, drink coffee with no or only a small amount of low fat milk, simply because milk slows down the absorption of caffeine.

If a person already drinks 3 to 6 cups of coffee a day, the pre-workout caffeine will do little for increasing energy levels or focus. The tolerance to caffeine will be so that the extra caffeine will make little difference. For the person who does not drink coffee or other caffeinated drinks (e.g. Red Bull and Coke etc) regularly, the caffeine might give a slight energy boost for the workout.

Are there Side effects?
When caffeine is consumed in large quantities, it’s side effects include anxiety, trembling and sleeplessness. If you are sensitive to caffeine, it is best to avoid it. Scientific research shows there is no link between long term caffeine use and health problems. However, there is a connection between raised cholesterol levels and heavy coffee consumption which is caused by certain fats in coffee.

Appendix
Data from Bridge et al. (2000) show that caffeine increases endurance time at 75% VO2max. This study also demonstrated the positive effect of caffeine on athletes’ rate of perceived exertion during exercise for 45min. Similarly, Graham & Spreit (1991) reported an increased time to exhaustion in athletes exercising at 85% VO2max following caffeine ingestion at 9mg per kilogram of body weight.